There are conventionally-known disk-scanning-type confocal microscopes that are provided with a disk unit in which a microlens array and a pinhole array having the same pattern are integrally assembled (for example, see PTL 1 and PTL 2).
In the confocal microscope described in PTL 1, a shift of the illumination light axis due to a dichroic mirror is corrected by inclining the angle of the optical axis of illumination light with respect to the incident axis of the microlens array or by inclining the installation angle of the disk unit with respect to the incident axis of an objective lens. In the confocal microscope described in PTL 2, it is possible to switch among a plurality of disk units that have different pinhole diameters, and the incident angle of illumination light with respect to the disk unit is adjusted in conjunction with the switching of the disk units, thereby avoiding a reduction in the amount of light passing through the pinholes and improving the signal-to-noise ratio of the image.